package com.filter;

import java.io.IOException;
import java.io.PrintWriter;
import java.net.URLEncoder;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class LoginFilter implements Filter{

	public void destroy() {
		// TODO Auto-generated method stub
		
	}

	public void doFilter(ServletRequest request,ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		HttpServletRequest req=(HttpServletRequest)request;
		HttpServletResponse res=(HttpServletResponse)response;
		HttpSession session=req.getSession();
	
		if(session.getAttribute("username")!=null){
			chain.doFilter(request,response);	
		}else{
			
			PrintWriter out = response.getWriter();
			String message = URLEncoder.encode("请先登录,是否返回到登录页面?", "UTF-8");
			out.print("<script>");
			out.print("if(confirm(decodeURIComponent('"+message+"')))");
			out.print("{location.href='login.html';}");
			out.print("</script>");
		}
	}

	public void init(FilterConfig arg0) throws ServletException {
		// TODO Auto-generated method stub
		System.out.println("initFilter:"+11111);
	}

}
